Ogee refers to the curved shape of this large, cast iron washer which is typically used in dock and wood construction. These oversized washers have a large bearing surface designed to prevent bolt heads and nuts from pulling into the wood. ASTM A48 covers Gray Iron Castings, including ogee washers.
Dimensions
| Bolt Size | A | B | T | Weight (lbs.) Per 100 Pieces | Part Number |
|---|---|---|---|---|---|
| Top Outside Diameter | Bottom Outside Diameter | Thickness | Galvanized | ||
| 1⁄2 | 13⁄8 | 23⁄8 | 1⁄2 | 48 | 18991 |
| 5⁄8 | 15⁄8 | 23⁄4 | 5⁄8 | 62 | 18992 |
| 3⁄4 | 17⁄8 | 3 | 3⁄4 | 71 | 18066 |
| 7⁄8 | 2 | 31⁄2 | 7⁄8 | 115 | 18998 |
| 1 | 21⁄2 | 4 | 1 | 150 | 18999 |
| 11⁄8 | 21⁄2 | 41⁄4 | 11⁄8 | 249 | 19206 |
| 11⁄4 | 21⁄2 | 41⁄2 | 11⁄4 | 286 | - |
| 11⁄2 | 3 | 51⁄2 | 11⁄2 | 412 | - |
| Reference ASTM A48 - Standard Specification for Gray Iron Castings | |||||
FAQs
An ogee washer is a large, cast iron washer featuring a distinct curved or contoured profile, known as an ogee shape. This design provides an oversized bearing surface that helps distribute load pressure and prevents bolt heads or nuts from pulling into timber or other softer materials. Ogee washers are primarily used in dock, bridge, and heavy timber construction, where they offer both structural strength and a clean, finished appearance.
The term ogee refers to the gracefully curved S-shaped contour that defines the washer’s outer profile. This curve not only gives the washer its characteristic look but also helps disperse load evenly while maintaining a low, rounded profile that blends smoothly against wood surfaces. The ogee shape also adds thickness and strength to the washer without unnecessary weight, making it both functional and aesthetically appealing for visible applications.
Ogee washers are used in a wide range of wood and marine construction projects, including piers, docks, timber bridges, retaining walls, and heavy timber framing. They are particularly common in marine and waterfront structures, where their wide bearing surface and corrosion-resistant finish prevent fasteners from embedding into the wood over time. In these applications, ogee washers are often paired with timber bolts or square head bolts to create strong, secure, and visually consistent connections.
Ogee washers differ from other washer types in both material and geometry.
While flat washers are thin, stamped from sheet metal, and provide minimal bearing area, ogee washers are cast from gray iron and significantly thicker, allowing them to withstand heavy compression without distortion. Compared to malleable iron washers, ogee washers are generally more refined in shape, offering a curved profile rather than a flat or slightly chamfered edge. This makes ogee washers ideal when both strength and aesthetics are important, particularly in exposed wood structures where the washer remains visible after installation.
Ogee washers are typically made from gray cast iron and are covered under ASTM A48 – Standard Specification for Gray Iron Castings.
This standard ensures proper hardness, tensile strength, and casting quality for structural applications. Ogee washers are available in plain or hot-dip galvanized finishes, depending on project requirements. The galvanized option provides enhanced corrosion resistance, making it suitable for outdoor and marine environments.
Ogee washers provide several structural and practical benefits in timber applications:
- Their large bearing surface spreads load over a wider area, preventing bolt heads or nuts from embedding into the wood.
- The cast iron composition offers high compressive strength, ensuring that the washer retains its shape under heavy torque or pressure.
- The curved profile reduces stress concentrations and provides a clean, professional finish in visible applications.
- When hot-dip galvanized, they offer long-term resistance to corrosion, even in coastal or humid environments.
These advantages make ogee washers a preferred choice for timber bridge decks, pier supports, and dock assemblies.
While both ogee and plate washers serve the purpose of distributing load over a large surface area, they differ in design and application.
Plate washers are typically flat, square, or rectangular, fabricated from steel plate, and used where maximum bearing area is required, such as in anchor bolt assemblies or seismic applications. Ogee washers, on the other hand, are cast and curved, offering a decorative yet functional profile that complements timber and marine environments. Ogee washers are chosen when the structure calls for both strength and aesthetic appeal, whereas plate washers prioritize maximum structural capacity.
Portland Bolt supplies ogee washers in standard diameters ranging from ½″ through 1″, matching the most common timber bolt and rod sizes.
Typical specifications include:
- Material: Gray cast iron per ASTM A48
- Diameter range: ½″ – 1″
- Finish options: Plain or hot-dip galvanized
- Origin: Domestic and import options available
The galvanized finish is recommended for marine, dock, and exterior use, while the plain finish is suitable for interior or non-corrosive environments.
Ogee washers are especially well-suited for marine and dock construction because their thick, cast profile resists compression in large timber assemblies that are exposed to fluctuating moisture and environmental conditions. The curved shape provides a smoother, snag-free surface compared to flat washers, reducing damage risk to ropes, equipment, or personnel. When hot-dip galvanized, ogee washers offer excellent corrosion resistance against saltwater exposure, ensuring long-term reliability in coastal and waterfront structures.
Yes. Ogee washers are compatible with most timber fasteners, including timber bolts, square head bolts, and anchor rods used in wood construction. They are particularly effective when used with large-diameter bolts in applications where the fastener head or nut bears directly against wood. For proper performance, ogee washers should be installed with the curved face up, seated directly under the nut or bolt head to ensure even load distribution and a secure connection.
Portland Bolt supplies ogee washers that conform to ASTM A48 casting standards and inspects all incoming lots for dimensional accuracy, surface integrity, and finish quality. Galvanized washers are processed under controlled conditions to ensure consistent zinc coating thickness and adhesion. Customers requiring Buy America compliance, dimensional certification, or specific coating requirements can work directly with Portland Bolt to verify compliance prior to shipment.
Yes. Portland Bolt maintains a stock of common ogee washer sizes in both plain and hot-dip galvanized finishes for quick turnaround. For less common sizes, finishes, or special requirements, custom runs can be arranged. Customers are encouraged to confirm stock availability prior to ordering, especially for large-volume marine or infrastructure projects.